void OnGroupChatPresenceError(XmppGroupChatModel chat, Presence pres)
{
if (pres.Error != null &&
pres.Error.Type == ErrorType.cancel &&
pres.Error.Condition == ErrorCondition.Conflict) {
// nickname already in use; autorejoin with _ appended
JoinRoom(chat.ID, chat.OwnNickname + "_", chat.Password);
return;
}
var msg = CreateGroupChatPresenceErrorMessage(pres);
Session.AddMessageToChat(NetworkChat, msg);
Session.RemoveChat(chat);
}